We start by mixing 1/2 tsp Yeast, 1/2 cup Warm water and 1/2 cup Flour in a large bowl and set it aside to get frothy. Mash your potatoes at this stage.
Once there are bubbles on the surface of the yeast mixture, we add the 1 cup Mashed potato, 2 tsp Sugar, 1 1/4 tsp Salt, 3 tbsp Butter (melted), 3 cups Flour and half an egg. We save the other half for the egg wash later. Using your hands, mix the ingredients together until sticky.
Oil your kitchen counter top and your hands, dump the dough onto the oiled surface and start kneading it. It will be sticky but as you knead it the dough with come together. If after 3-5 mins the dough is still very sticky add 1 tbsp flour to bring it together. I always like using oil instead of flour as flour can dry out the buns as they bake making them dense and dry.
Ounce the dough is smooth, oil the mixing bowl you used to mix the ingredients and place the dough in it. Cover with cling wrap and let it rise for at least an hour or until it has doubled in volume.
Knock back all the air and transfer the dough to an oiled kitchen counter top. Divide the dough into 8-10 pieces. Roll the dough into balls using the pressure from the palm of your hand and the kitchen counter top.
Once you have a smooth ball, place on a lined baking tray. Repeat until all are done. If you are okay with the buns baking into each other and creating a tare-apart situation then don’t space them too far from each other. I wanted them separate hence I baked four on a tray to avoid them touching as they bake. Let these rise for 10-15 mins, covered.
With the remming egg, brush each bun liberally and top with sesame seeds or onion seeds, some sea salt as well. Bake for 15-20 mins at 200℃. Check them at 15 mins, they should be risen, golden and dry to the touch.
Once baked they will have a hollow sound if tapped. It will be crusty while it's hot, as it cols down, they will get softer and fluffier. Serve warm with some butter.